@inproceedings{ovidiu2008subriemannian,
title={SUBRIEMANNIAN GEOMETRY, A VARIATIONAL APPROACH},
author={Ovidiu Calin, and Der-Chen Chang},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160909134813513102734},
booktitle={Journal of Differential Geometry},
volume={80},
number={1},
pages={23-43},
year={2008},
}
Ovidiu Calin, and Der-Chen Chang. SUBRIEMANNIAN GEOMETRY, A VARIATIONAL APPROACH. 2008. Vol. 80. In Journal of Differential Geometry. pp.23-43. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160909134813513102734.